Detecting and Treating Nervous System Disorders

ABSTRACT

Some embodiments of a mapping device may be capable of passing through cerebral veins and other cerebrovascular spaces to provide electrophysiological mapping of the brain. These embodiments of the device may also be capable of providing, simultaneously or separately, ablation energy or other treatments to targeted brain tissue. In such circumstances, a user may be enabled to analyze an electrophysiological map of a patient&#39;s brain and, at the same time or within a short time period before or after the mapping process, may be enabled to apply ablation energy for treatment of a central nervous system disorder. Such treatment may be accomplished without the use of invasive surgery in which the brain is accessed through an opening in the patient&#39;s cranium.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of (and claims priority to) U.S.Provisional Application Ser. No. 60/738,718, filed on Nov. 22, 2005 byAsirvatham et al. and entitled “Detecting And Treating Nervous SystemDisorders,” the entire contents of which is incorporated herein byreference.

TECHNICAL FIELD

This document relates to detection and treatment of one or more nervoussystem disorders.

BACKGROUND

Some disorders of the nervous system may be traced to particularportions of the brain. For example, Epilepsy is a nervous systemdisorder that can cause seizures due to abnormal electrical activity ina particular portion of the brain. Epilepsy affects approximately 50,000to 100,000 people per year in the United States and is known to affectpeople of all age groups.

The abnormal electrical activity that occurs in the brain during anEpileptic seizure may be focused in the different portions of the braindepending upon the patient. As such, a patient's brain may be “mapped”to determine a particular portion of the brain that requires treatment.The mapping process may be accomplished using electroencephalogram (EEG)sensors placed on the outside of the patient's scalp, using magneticresonance imaging (MRI) technique, or using electrocorticography (ECoG)electrodes placed on the outside of the brain through an opening formedin the patient's cranium. In general, the noninvasive methods of mappingthe brain provide limited resolution compared to the more invasivemethods that require access to the brain through a opening formed in thecranium, yet these invasive methods are often associated with aprolonged recovery period and an increased risk of morbidity.

Epilepsy and some other nervous system disorders can be treated withdrug therapy or surgery. In many cases, the drugs are not fullyeffective for purposes of treating the disorder (e.g., epilepticseizures may still occur even with the treatment of drug therapy). Also,some of the drugs used to treat the nervous system disorder may haveharmful or undesirable side effects.

Surgical treatment for Epilepsy and other nervous system disorderstypically requires a surgeon to cut an opening in the patient's cranium.After the targeted area has been determined (e.g., using a mappingtechnique), the surgeon may remove the targeted brain tissue through theopening formed in the patient's cranium. Alternatively or in addition,the surgeon may insert electrodes through the opening in the patient'scranium into the targeted brain tissue to provide electrical stimulationto that area of the brain. For example, deep brain stimulation (DBS) isa technique, conventionally used to treat Parkinson's Disease and othernervous system disorders, in which the stimulation electrode is advancedthrough the opening in the patient's cranium to the thalamus or otherarea deep in the brain. These surgical techniques may be significantlyinvasive (e.g., requires an opening formed in the patient's cranium orrequires access to the brain via the cerebrospinal fluid), whichtypically results in prolonged recovery times and, in somecircumstances, an increased risk of morbidity.

SUMMARY

Some embodiments of a mapping device may be capable of passing throughcerebral veins and other cerebrovascular spaces to provideelectrophysiological mapping of the brain. These embodiments may also becapable of providing, simultaneously, sequentially, or separately,ablation energy (e.g., RF energy, ultrasound energy, microwave energy,or the like) or other treatments to targeted brain tissue. In suchcircumstances, a user may be enabled to analyze an electrophysiologicalmap of a patient's brain and, at the same time or within a short timeperiod before or after the mapping process, may be enabled to applyablation energy for treatment of a nervous system disorder. Suchtreatment may be accomplished without the use of invasive surgery inwhich the brain is accessed through an opening in the patient's cranium.Furthermore, in some circumstances, such access to the brain may allowearly detection of an impending vascular event (e.g., a stroke) orelectrical event (e.g., a seizure).

In some embodiments, an electrophysiological brain mapping device mayinclude an elongated body having a distal end to pass through one ormore cerebral veins proximal to brain tissue. The elongated body maydefine a fluid input conduit in fluid communication with a fluid inputport near the distal end and may be a drain conduit in fluidcommunication with a drain port near the distal end. The device may alsoinclude one or more electrodes to detect electrophysiological signals ina portion of the brain and to deliver ablation energy. The electrodesmay be disposed near the distal end of the elongated body. The devicemay further include a balloon structure disposed near the distal end soas to surround the fluid input port, the drain port, and the electrodes.The balloon structure may be adjustable from a non-expanded state to anexpanded state when a fluid flows from the input port and to the drainport.

In other embodiments, an implantable control device for predicting animminent event in a brain may include a housing implantable in a body ofa patient. The device may also include a controller circuit at leastpartially disposed in the housing. The controller circuit may compriseat least one filter to receive electrophysiological signals detected byone or more electrodes disposed in a portion of a brain. The device mayfurther include a wireless transmitter to transmit a signal to a deviceoutside the body of the patient in response to abnormal brain activitydetected by the electrodes. The wireless transmitter may be electricallycoupled to the controller circuit.

These and other embodiments may provide one or more of the followingadvantages. First, some embodiments of the devices and methods describedherein provide a noninvasive, high-resolution process of mappingparticular portions of the brain. For example, the use of EEG electrodeplaced on the outside of a patient's scalp provides a noninvasiveprocess for mapping the patient's brain, but the resolution of theexternal EEG monitoring process is not as detailed as the more invasiveECoG process in which electrodes are placed directly on the brainthrough an opening in the patient's cranium (e.g., a significant portionof the signal “spikes” sensed by the ECoG process are not sensed by theEEG process). As described in more detail below, some embodiments of thedevices and methods described herein provide a noninvasive process fordisposing sensor electrodes (e.g., EEG electrodes or the like) and formapping at least a portion of the brain with substantially higherresolution that typical external mapping processes. Moreover, thedevices and method described herein permit such high resolution mappingof the brain without necessarily requiring surgery in which an openingis formed in the patient's cranium. As such, the patient recovery timemay be substantially reduced and, in some circumstances, the risk ofmorbidity may be substantially reduced.

Second, the devices and methods described herein may provide forcontemporaneous mapping and treatment or at least a portion of thebrain. For example, a catheter device may be used to deliver electrodesto the brain for sensing electrical signals to map the brain, and thecatheter device may also include instrumentation for ablating orotherwise treating brain tissue affected by a nervous system disorder(e.g., Epilepsy or the like). In such circumstances, the pathologicalsite or targeted brain tissue may be treated without the need forinvasive surgery in which brain tissue is cut and removed though anopening formed in the patient's cranium. Thus, the targeted portion ofthe brain may be contemporaneously mapped and treated in a manner thatcan substantially reduce the patient recovery time and the risk ofmorbidity. The high resolution afforded by the mapping is also appliedto the treatment, which is focally delivered to affect target tissueswith a reduced likelihood of collateral tissue damage. While epilepsymay be referred to frequently in this document, it should be understoodthat many conditions including dyslexia or memory disruption,obsessive-compulsive disorder, depression, and others may have similarlocalized electrical conditions as their mechanism. The mapping andtherapy techniques described herein may apply to sufferer's of theseconditions as well.

Third, the devices and methods described herein may nonsurgicallydeliver electrodes and/or treatment instrumentation to the brain usingcerebral veins and other cerebrovascular spaces. Delivering theelectrodes through the venous system (which is generally a lowerpressure environment) may reduce the risk of bleeding or stroke theprocedures described herein. For example, such low pressure vessels mayact as a conduit to permit catheter placement of electrodes adjacent totarget tissues. If closer placement is required, these low pressurevessels may be exited. In some circumstances, venous travel minimizedthe amount of nervous tissue that must be traversed before therapydelivery. Thus, in some embodiments, a user may nonsurgically deliverelectrodes and/or treatment instrumentation to targeted portions of thebrain, including portions in the frontal lobe, parietal lobe, occipitallobe, temporal lobe, thalamus, hypothalamus, and the like. For example,some of the devices described herein may be capable of targeting andablating neurons in the arcuate nucleus of the hypothalamus so as totreat obesity or other conditions.

Fourth, some embodiments of the catheter device may employ a coolingsystem to both internally cool the catheter and to externally cool thesurrounding the distal end of the catheter. This dual-action coolingcatheter may permit greater ablation energy, such as heat, to bedelivered to targeted portions of the brain with causing excess damageto non-targeted portions. While therapy to nervous tissues is discussedherein, it should be understood that this type of dual-action coolingcatheter may be useful in many applications in medicine, such as theablation energy treatment of fatty tissues or in regions of limitedblood flow.

Fifth, some embodiments of the devices and methods described herein mayinclude an implantable control unit that is electrically coupled to thesensor electrodes delivered to the brain. As previously described, thesensor electrodes may be capable of providing a high resolution map ofthe electrophysiological signals of at least a portion of the brain. Inresponse to these signals or in response to other inputs, theimplantable control unit include computer-implemented program to predictan imminent vascular event (e.g., a stroke) or electrical event (e.g., aseizure). Detection of an imminent event may be provided, in someembodiments, by detection of changes in electrical nervous activity thatantecede the clinical event (e.g. pre-seizure electrical changes), bydetection of changes in electrical events cause by ischemia (beforefrank stroke occurs), or by recording other modalities. Other suchmodalities could include Doppler signals of the arteries to the brain(which lie adjacent to the veins used by these implantable devices).Moreover, in some embodiments, the control unit may be configured totreat (e.g., deliver a medicament, deliver electrical stimulation,deliver ablation energy, or the like) a particular portion of the brainin response to the sensor signals from the electrodes or in response tothe prediction of the imminent vascular event or electrical event. Othertherapies provided by the control unit may include bursts of rapid,painless pacing to “reset” the fast electrical activity giving rise to aseizure, or delivery of a low energy shock via electrodes placedvenously proximate to nervous tissue so that a small energy deliverywould suffice. Alternatively, in other embodiments, rather than therapy,patient warning (e.g., an audible alert, a small shock, or a GPS-basedsignal to a medical service) could be issued.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a mapping electrode device delivered through avein to a brain, in accordance with some embodiments of the invention.

FIG. 2 is a side view of a plurality of mapping electrode devicesdelivered through the venous system to certain portions of a brain, inaccordance with some embodiments of the invention.

FIGS. 3A-B are a side views of a mapping-ablation device deliveredthrough a vein to a particular portion of a brain, in accordance withsome embodiments of the invention.

FIG. 4 is a side view of a plurality of a mapping-ablation devicesdelivered through veins to targeted portions of a brain.

FIG. 5A-B are a side views of another embodiment of a mapping-ablationdevice delivered through a vein to a particular portion of a brain.

FIGS. 6A-E is a side view of a mapping-ablation device being advancedtoward targeted brain tissue, in accordance with certain embodiments ofthe invention.

FIGS. 7A-C are magnified views of some embodiments of a mapping-ablationdevice.

FIGS. 8A-B are cross-sectional views of other embodiments of amapping-ablation device.

FIG. 9A-B is a side view of another embodiment of a mapping-ablationdevice and an implantable control unit.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring to FIG. 1, some embodiments of a mapping electrode device 100may include an elongated body 110 and one or more electrodes near adistal end 112 of the elongated body 110. In this embodiment, the device100 includes two electrodes 120 and 122 that are capable of detectingelectrophysiological signals in a portion of a brain 10, capable ofdetecting impedance parameters in a portion of the brain 10, or both.The elongated body 110 may comprise a flexible, biocompatible materialso that the electrodes 120 and 122 may be delivered be delivered to atargeted portion of the brain via cerebral veins 20 or othercerebrovascular spaces. As such, the electrodes 120 and 122 of themapping electrode device 100 may provide a relatively high-resolutionprocess of mapping particular portions of the brain 10 without the useof invasive surgery in which the brain 10 is accessed through an openingin the patient's cranium.

The elongated body 110 may comprise a flexible catheter having a conduitthrough which one or more electrical wires or conductive lines (notshown in FIG. 1) may pass. The electrical wires may extend through theelongated body 110 so as to electrically couple to the electrodes 120and 122 near the distal end 112 of the body 110. As described in moredetail below, the electrical wires may extend out of a proximal end (notshown in FIG. 1) of the elongated body 110 so as to electrically couplewith a control unit, such as an electrophysiological mapping control anddisplay system or an implantable control unit (described in more detailbelow).

The distal end 112 of the elongated body 110 may percutaneously enterthe patent's venous system via the femoral vein or via the jugular vein.For example, the device 100 depicted in FIG. 1 may percutaneously enterinto the patient's jugular vein and then pass through one or morecerebral veins 20 into a particular portion of the patient's brain 10.The distal end 112 of the elongated body 110 may be steerable so thatthe electrodes 120 and 122 may be delivered to the targeted portion ofthe brain (e.g., the parietal lobe, the temporal lobe, the occipitallobe, the frontal lobe, the thalamus, or the like) through one or morecerebral veins 20. For example, the device 100 may include ashape-memory member or one or more steering wires to cause the distalend 112 to bend in a particular direction. As such, a user may steer thedistal end 112 of the elongated body 110 into a desired vein, therebydirecting the electrodes 120 and 122 to a particular portion of thebrain 10. In another example, the device 100 may include a conduit orlumen extending therethrough that is capable of sliding over a guidewire. As such, the distal end 112 of the device 100 may include aconduit opening to receive a guide wire that was previously delivered tothe targeted portion of the patient's brain 10. The user may thendeliver the electrodes 120 and 122 to the targeted portion by slidingthe device 100 over the guide wire. In these embodiments, the outerdiameter of the elongated body 110 may be sized to safely pass throughthe inside of various cerebral veins 20.

In one implementation, the mapping electrode device 100 maypercutaneously enter the venous system through the patient's jugularvein. From there, the user may direct the distal end 112 of theelongated body 110 through one or more cerebral veins 20 toward atargeted portion of the patient's brain 10. In this embodiment, thedistal end 112 is directed to a portion of the brains' parietal lobe.When the mapping electrode device 100 is delivered to the targetedportion of the brain 10, the one or more electrical wires may extend outfrom proximal end (not shown in FIG. 1) of the elongated body and may beconnected to an electrophysiological mapping and display system (e.g., adigital EEG display system or the like) located near the patient's body.In such circumstances, the electrodes 120 and 122 disposed in a portionof the patient's brain 10 may detect the electrophysiological signalsoccurring in that portion of the patient's brain, and such signals maybe received by the mapping and display system so that the one or moresignals may be viewed in a display screen 130. Accordingly, a user mayview a high-resolution map (e.g., greater resolution that a traditionalexternal EEG procedure) of at least a portion of the patient's brainwithout an invasive procedure that requires an opening to be formed inthe patient's cranium. In this example depicted in FIG. 1, twoelectrodes are described, but it should be understood that the device100 may employ three or more electrodes along the length of device 100to permit simultaneous mapping from multiple regions of nervous tissue.In such embodiments, these electrodes may be small to enhance mappingresolution and may be electronically “wired together” to record from alarger area, or when needed for therapy delivery (described in moredetail below).

As described in more detail below, some embodiments of the electrodedevice 100 may be capable of contemporaneously mapping and ablating atargeted portion of the patient's brain 10. In such circumstances, auser may be enabled to analyze an electrophysiological map of apatient's brain and, at the same time or within a short time periodbefore or after the mapping process, may be enabled to apply ablationenergy for treatment of a nervous system disorder.

Referring to FIG. 2, some embodiments of a mapping electrode device 200may include a plurality of elongated bodies 210, 220, 230, and 240 thatcan be separately delivered to different portions of the brain 10. Eachof the elongated bodies 210, 220, 230, and 240 may include a pluralityof electrodes near the distal end 212, 222, 232, and 242, respectively.(It should be understood that, in some embodiments, the “distal end” mayextend quite proximally, so that electrodes span the a substantialportion of the distance the elongated body is in the brain.) Forexample, the elongated body 210 may include five electrodes 215, 26,217, 218, and 219 disposed near the distal end 212. As previouslydescribed, the five electrodes 215, 26, 217, 218, and 219 may beelectrically coupled to one or more wires passing through a conduit inthe elongated body 210 so that electrophysiological signals in the brain10 detected by the five electrodes 215, 26, 217, 218, and 219 may betransmitted to an implantable control unit or an electrophysiologicalmapping and display system (e.g., a digital EEG display system or thelike).

The other elongated bodies 220, 230, and 240 may also include associatedelectrodes. In this non-limiting example, elongated body 220 may includefive electrodes 225, 226, 227, 228, and 229 near its distal end 222.Also, elongated body 230 may include five electrodes 235, 236, 237, 238,and 239 near its distal end 232. Further, elongated body 240 may includefive electrodes 245, 246, 247, 248, and 249 near its distal end 242. Theelectrodes disposed on the elongated bodies 220, 230, and 240 may beelectrically coupled to one or more wires passing through a conduit inthe associated elongated body. As such, electrophysiological signals inthe brain 10 detected by the electrodes disposed on the elongated bodies220, 230, and 240 may be transmitted to an implantable control unit oran electrophysiological mapping and display system (e.g., a digital EEGdisplay system or the like).

Still referring to FIG. 2, each of the elongated bodies 210, 220, 230,and 240 may comprise a flexible, biocompatible material so that theelectrodes disposed thereon may be delivered be delivered to a targetedportion of the brain via cerebral veins 20 or other cerebrovascularspaces. For example, the elongated bodies 210, 220, 230, and 240 maycomprise flexible catheters having at least one conduit through whichone or more electrical wires or conductive lines (not shown in FIG. 2)may pass. As previously described, the electrodes disposed near thedistal end of each the elongated bodies 210, 220, 230, and 240 mayprovide a relatively high-resolution map of particular portions of thebrain 10 without the use of invasive surgery in which the brain 10 isaccessed through an opening formed in the patient's cranium.

The distal ends 212, 222, 232, and 242 of the elongated bodies 210, 220,230, and 240 may percutaneously enter the patent's venous system via thefemoral vein or via the jugular vein. For example, the device 200depicted in FIG. 2 may include a guide catheter 205 that percutaneouslyenters into the patient's jugular vein and then passes toward one ormore cerebral veins 20. Then, one of the elongated bodies 210, 220, 230,and 240 may be delivered into the jugular vein through the guidecatheter 205 and toward a targeted portion of the brain 10. For example,the distal end 242 of the elongated body 240 may be delivered to afrontal lobe portion of the brain 10 before the other elongated bodies230, 220, and 210 are delivered to other portions of the brain throughthe guide catheter 205.

Still referring to FIG. 2, the distal ends 212, 222, 232, and 242 of theelongated bodies 210, 220, 230, and 240 may be steerable so that theelectrodes disposed thereon may be delivered to the targeted portion ofthe brain through one or more cerebral veins 20. As previouslydescribed, each of the elongated bodies 210, 220, 230, and 240 mayinclude a shape-memory member or one or more steering wires to cause thedistal end to bend in a particular direction. As such, a user may steerthe distal end 212, 222, 232, or 242 into a desired vein, therebydirecting the associated electrodes to a particular portion of the brain10. In another example, each of the elongated bodies 210, 220, 230, and240 may include a conduit extending therethrough that is capable ofsliding over a guide wire. As such, the distal ends 212, 222, 232, and242 may include a conduit opening to receive an associated guide wirethat was previously delivered to the targeted portion of the patient'sbrain 10. In these embodiments, the outer diameter of the elongatedbodies 210, 220, 230, and 240 may be sized so that a plurality of theelongated bodies 210, 220, 230, and 240 may pass side-by-side throughthe inside of various cerebral veins 20.

In one exemplary implementation, the mapping electrode device 200 maypercutaneously enter the venous system through the patient's jugularvein. From there, the user may direct the distal ends 212, 222, 232, and242 of the elongated bodies 210, 220, 230, and 240 through one or morecerebral veins 20 toward their respective targeted portions of thepatient's brain 10. In this embodiment, the distal end 242 of oneelongated body 240 (labeled as “D” in FIG. 2) is directed to a frontallobe portion of the brain 10, the distal ends 232 and 222 of theelongated bodies 230 and 220 (labeled as “C” and “B” in FIG. 2) aredirected to different areas in a parietal lobe portion of the brain 10,and the distal end 212 of the elongated body 210 (labeled as “A” in FIG.2) is directed to an occipital lobe portion of the brain 10. When themapping electrode device 200 is delivered to the multiple targetedportions of the brain 10, the one or more electrical wires may extendout from proximal ends (not shown in FIG. 2) of the elongated bodies210, 220, 230, and 240 and may be connected to an electrophysiologicalmapping and display system (e.g., a digital EEG display system or thelike) located near the patient's body.

As previously described, the electrodes disposed in targeted portions ofthe patient's brain 10 may detect the electrophysiological signalsoccurring in that portion of the patient's brain, and such signals maybe received by the mapping and display system so that the one or moresignals may be viewed in display screens 250 and 260. For example, afirst display screen 250 may display the electrophysiological signalsdetected by electrodes in different portions of the brain 10. The seconddisplay screen 260 may display the signals detected by electrodesdisposed 215, 216, 217, 218, and 219 on the same elongated body 210. Insuch circumstances, the first screen 250 may display signals the providean electrophysiological map of the brain 10 while the second screen 260permits a user to focus on the signals detected near an electricalevent, such as a seizure focus 215. By providing a map of differentportions of the brain, a user may be capable of detecting which portionis experiencing an electrical event (e.g., a seizure focus 215), and theuser may refer to the second screen 260 to provide a more detailedanalysis of the electrophysiological map in that particular portion ofthe brain 10. Such a detailed analysis may provide the user with anopportunity to accurately determine the coordinates of the brain portionthat requires treatment, such as ablation energy to a specific portionof the brain 10. Again, the mapping electrode device 200 may provide ahigh-resolution map (e.g., greater resolution that a traditionalexternal EEG procedure) of different portions of the patient's brain 10without an invasive procedure that requires an opening to be formed inthe patient's cranium.

Furthermore, the relative anatomic positions of each of the elongatedbodies (210, 220, 230, 240) may be known by a number of techniques. Onesuch technique may include placement of unique fluoroscopic markers oneach elongated body to permit its radiographic identification whiledeployed in the brain. In another technique, an electrical field isapplied externally and recorded on each of the electrodes. The relativestrength of the electric fields in each electrode determines itsposition. Three dimensional localization may be accomplished usingorthogonal electric fields of low energy each uniquely encoded with adifferent frequency or using temporally encoded permit three dimensionallocalization. These positions of the elongated body can be registeredusing computer software with previously acquired CT or MRI images topermit identification of catheter positions with the nervous system. Analternate technique would deliver low energy signals (electrical orultrasound) from the electrodes to permit their localization by means ofrelative energy strength at other electrode recording sites. Preciselocalization would permit selection of specific electrodes for therapydelivery, as described in more detail below.

As described in more detail below, some embodiments of the elongatedbodies 210, 220, 230, and 240 may be capable of contemporaneouslymapping and ablating a targeted portion of the patient's brain 10. Insuch circumstances, a user may be enabled to analyze anelectrophysiological map of a patient's brain and, at the same time orwithin a short time period before or after the mapping process, may beable to apply ablation energy for treatment of a nervous systemdisorder.

Referring now to FIGS. 3A-B, a mapping-ablation device 300 may includean elongated body 310 and one or more electrodes disposed near a distalend 312 of the elongated body 310. The electrodes may be electricallycoupled to one or more wires (or conductive traces) passing through aconduit of the elongated body 310. In such circumstances, the electrodesmay be capable of detecting electrophysiological signals in at least aportion of the patient's brain 10 and may be capable ofcontemporaneously delivering ablation energy to that portion of thebrain 10. For example, the electrodes may be configured to deliver radiofrequency (RF) ablation energy or ultrasound ablation energy so as totreat a particular portion of the brain 10 that is affected by a nervoussystem disorder.

In this embodiments, the mapping-ablation device 300 includes twoelectrodes 320 and 322 disposed near the distal end 312. The electrodes320 and 322 may be configured to detect electrophysiological signals inat least a portion of the brain 10 and may be configured tocontemporaneously delivery RF ablation energy to that portion of thebrain. As such, a user may (1) access the targeted portion of the brain10 via one or more cerebral veins 20, (2) detect signals in at leastthat portion of the brain 10 so as to view a high-resolution map, (3)deliver ablation energy to that portion of the brain 10 to treat anervous system disorder, and (4) detect signals in that portion of thebrain again to determine the effectiveness of the ablation treatment.Moreover, the user may perform this process or other processes withoutan invasive procedure that requires an opening to be formed in thepatient's cranium

Still referring to FIGS. 3A-B, the elongated body 310 may comprise aflexible catheter having a conduit through which one or more electricalwires or conductive lines (not shown in FIG. 3) may pass. The electricalwires may extend out of a proximal end (not shown in FIG. 3) of theelongated body 310 so as to electrically couple with a control unit,such as an electrophysiological mapping control and display system or animplantable control unit. The distal end 312 of the elongated body 310may percutaneously enter the patent's venous system via the femoral veinor via the jugular vein. Also, the distal end 312 of the elongated body310 may be steerable so that the electrodes 320 and 322 may be deliveredto the targeted portion of the brain through one or more cerebral veins20. For example, the elongated body 310 may include a conduit extendingtherethrough that is capable of sliding over a guide wire. The user maydeliver the electrodes 320 and 322 to the targeted portion of the brain10 by sliding the elongated body 310 over the guide wire. In suchembodiments, the outer diameter of the elongated body 310 may be sizedto safely pass through the inside of the cerebral veins 20.

In one exemplary implementation, a user may be able to analyze anelectrophysiological map of a patient's brain 10 and, at the same timeor within a short time period before or after the mapping process, maybe able to apply ablation energy for treatment of a nervous systemdisorder. As shown in FIGS. 3A-B, the mapping-ablation electrode device300 may percutaneously enter the venous system through the patient'sjugular vein, and the distal end 312 may be directed through one or morecerebral veins 20 toward a targeted portion of the patient's brain 10.(In this embodiment, the distal end 312 is directed to a temporal lobeportion of the brain 10.) The user may direct the electrodes 320 and 322to different portions of the brain 10 and therein detect theelectrophysiological signals to map at least a portion of the brain 10using, for example, an electrophysiological mapping and display system(e.g., a digital EEG display system or the like). If the mapping processdoes not reveal a portion of the brain 10 affected by a nervous systemdisorder, the user may direct the electrodes 320 and 322 to a differentportion of the brain 10.

If the mapping process reveals a portion of the brain 10 that isaffected by a nervous system disorder of otherwise requires treatment,the user may thereafter deliver ablation energy to the affected tissueusing the electrodes 320 and 322. For example, as shown in FIGS. 3A-B,if the mapping process determines the location of an electrical event,such as a seizure focus 315, in the brain 10, the electrodes 320 and 322may be used to delivery RF ablation energy to the brain tissue in theaffected portion of the brain. The RF energy may cause thermal ablationto the targeted tissue and render this tissue electrically inactive,which may prevent future occurrences of the electrical events (e.g.,seizure focus 315) associated with the nervous system disorder.Accordingly, in some embodiments, a user may view a high-resolution mapof at least a portion of the patient's brain and may contemporaneouslytreat that portion of the brain with ablation energy, all of which maybe accomplished without an invasive procedure that requires an openingto be formed in the patient's cranium.

In an alternate embodiment, multiple electrodes may be disposed on theelongated body as shown in FIG. 2. Once the target tissue is identified,energy is delivered between the two (or more) electrodes that may besituated on any elongated member to select an energy path that treatstarget tissue while reducing the likelihood of collateral damage tohealthy tissues. Such an embodiment may permit high-resolution mappingwithout necessarily repositioning mapping catheters.

Referring to FIG. 4, some embodiments of a mapping-ablation device 400may employ different forms of ablation energy depending on the desiredtreatment, the affected tissue, quantity of energy delivered, and otherfactors. The mapping ablation devices may include one elongated body ora plurality of elongated members. The mapping-ablation device 400 mayinclude a first elongated body that is equipped to deliver a first typeof ablation energy (e.g., RF ablation energy, ultrasound ablationenergy, microwave ablation energy, laser ablation energy, or the like)and a second elongated body that is equipped to deliver a different typeof ablation energy Alternatively, all of the elongated bodies of themapping ablation device 400 may be equipped to deliver the same type ofablation energy.

For example, the mapping-ablation device 400 may include at least oneelongated body 410 having a distal end 412 and one or more ultrasoundablation transducers 415 disposed thereon. The elongated body mayinclude, in addition to the ultrasound transducers 415, one or moreelectrodes to map the electrophysiological signals in the brain 10.Alternatively, the mapping electrodes may also serve as the ultrasoundtransducers 415. In such embodiments, a user may view a high-resolutionmap of at least a portion of the patient's brain and maycontemporaneously treat that portion of the brain with ultrasoundablation energy, all of which may be accomplished without an invasiveprocedure that requires an opening to be formed in the patient'scranium.

In another example, the mapping-ablation device 400 may include at leastone elongated body 420 having a distal end 422 and one or more microwaveablation probes 425 disposed thereon. The elongated body may include, inaddition to the microwave ablation probes 425, one or more electrodes tomap the electrophysiological signals in the brain 10. Alternatively, themapping electrodes may also serve as the microwave ablation probes 425.Again, in these embodiments, a user may view a high-resolution map of atleast a portion of the patient's brain and may contemporaneously treatthat portion of the brain with microwave ablation energy without aninvasive procedure that requires an opening to be formed in thepatient's cranium.

In further example, the mapping-ablation device 400 may include a firstelongated body 430 having a distal end 432 and one or more RF ablationelectrodes 435 disposed thereon. Also, the mapping-ablation device 400may include a second elongated body 430 having a distal end 442 and oneor more RF ablation electrodes 445 disposed thereon. In suchcircumstances, the first and second elongated members may be used todeliver RF ablation energy to the tissue between the two different setsof electrodes 435 and 445. As previously described, the RF electrodes435 and 445 may also serve as the mapping electrodes so that a user mayview a high-resolution map of at least a portion of the patient's brainand may contemporaneously treat that portion of the brain with RFablation energy.

Still referring to FIG. 4, in yet another example, the mapping-ablationdevice 400 may include at least one elongated body 450 having a distalend 452 and one or more RF ablation electrodes 455 disposed thereon. Aspreviously described, the RF electrodes 455 and 445 may also serve asthe mapping electrodes. The RF electrodes 455 may interact withelectrodes on an external patch coupled to the outer surface of thepatient's scalp. In such circumstances, the elongated member 450 may beused to deliver RF ablation energy to the tissue between the electrodes455 and the patch 456. Again, in these embodiments, a user may view ahigh-resolution map of at least a portion of the patient's brain and maycontemporaneously treat that portion of the brain with RF ablationenergy without an invasive procedure that requires an opening to beformed in the patient's cranium.

In a further example, the mapping-ablation device 400 may include atleast one elongated body 460 having a distal end 462 and at least onemore laser ablation device 466 disposed thereon. The elongated body mayinclude, in addition to the laser ablation device 466, one or moreelectrodes 465 to map the electrophysiological signals in the brain 10.In these embodiments, a user may view a high-resolution map of at leasta portion of the patient's brain and may contemporaneously treat thatportion of the brain with laser ablation energy without an invasiveprocedure that requires an opening to be formed in the patient'scranium.

Referring now to FIGS. 5A-B, a mapping-ablation device 500 may includean elongated body 510 that is configured to slide over a guide wire 530in order to deliver one or more electrodes to a targeted portion of thebrain 10. In this embodiment, the device 500 includes two electrodes 520and 522 that are capable of detecting electrophysiological signals in aportion of a brain 10, capable of detecting impedance parameters in aportion of the brain 10, or both. The elongated body 510 may comprise aflexible catheter having a conduit through which one or more electricalwires or conductive lines (not shown in FIGS. 5A-B) may pass. Theelectrical wires may extend through the elongated body 510 so as toelectrically couple to the electrodes 520 and 522, and the electricalwires may extend out of a proximal end (not shown in FIGS. 5A-B) of theelongated body 510 so as to electrically couple with a control unit,such as an electrophysiological mapping control and display system or animplantable control unit.

The guide wire 530 may comprise a flexible, biocompatible materialhaving a distal end 532 that is steerable or may be controllablybendable. As such, the guide wire 530 may percutaneously enter thepatient's jugular or femoral vein and then may be directed to a targetedportion of the brain through one or more cerebral veins 20. Theelongated body 510 may include a conduit extending therethrough that iscapable of sliding over the guide wire 530. As such, the distal end 512of the elongated body 510 may include a conduit opening to receive theproximal end (not shown in FIGS. 5A-B) of the guide wire 530. The usermay then deliver the electrodes 520 and 522 to the targeted portion bysliding the elongated body 510 over the guide wire 530 toward the distalend 532 of the guide wire 530. In these embodiments, the outer diameterof the elongated body 510 may be sized to safely pass through the insideof various cerebral veins 20.

In one exemplary implementation, a user may be able to analyze anelectrophysiological map of a patient's brain 10 and, at the same timeor within a short time period before or after the mapping process, maybe able to apply ablation energy for treatment of a nervous systemdisorder. As shown in FIGS. 5A-B, the mapping-ablation electrode device500 may percutaneously enter the venous system through the patient'sjugular vein, and the distal end 512 may be guided over the wire 530through one or more cerebral veins 20 toward a targeted portion of thepatient's brain 10. (In this embodiment, the distal end 512 is directedto a temporal lobe portion of the brain 10.) The user may direct theelectrodes 520 and 522 to different portions of the brain 10 using theguide wire 530. In those different brain portions, the user may employthe electrodes 520 and 522 to detect the electrophysiological signals tomap at least a portion of the brain 10 using, for example, anelectrophysiological mapping and display system (e.g., a digital EEGdisplay system or the like). If the mapping process does not reveal aportion of the brain 10 that is affected by a nervous system disorder orthat otherwise requires treatment, the user may direct the electrodes520 and 522 to a different portion of the brain 10.

If the mapping process reveals a portion of the brain 10 that isaffected by a nervous system disorder of otherwise requires treatment,the user may thereafter deliver ablation energy to the affected tissueusing the electrodes 520 and 522. For example, as shown in FIGS. 5A-B,if the mapping process determines the location of an electrical event(e.g., a seizure focus 515) in the brain 10, the electrodes 520 and 522may be used to delivery RF ablation energy to the brain tissue in theaffected portion of the brain. Accordingly, in some embodiments, a usermay view a high-resolution map of at least a portion of the patient'sbrain and may contemporaneously treat that portion of the brain withablation energy, all of which may be accomplished without an invasiveprocedure that requires an opening to be formed in the patient'scranium.

In some circumstances, the guide wire 530 may be removed from the innerconduit of the elongated body 510 after the electrodes 520 and 522 aredelivered to a targeted portion of the brain 10. Then, the inner conduitmay be used to deliver a medicament delivery catheter (not shown inFIGS. 5A-B), such as a syringe catheter that is capable of dispensing acontrolled amount of a medicament or other chemical. For example, theinner conduit of the elongated body may be used to direct a syringecatheter containing a chemical solution used to treat the body tissueafter the ablation process. In another example, the electrodes may beused to map a particular portion of the brain so as to identify avascular event (e.g., a stroke) or an electrical event (e.g., a seizure)in which the selected treatment may require dispersion of medicament orother chemical without the use of ablation. In these examples, the guidewire 530 and the inner conduit of the elongated body 510 may be employedto deliver the electrodes 520 and 522 to a targeted brain portion, andthe inner conduit may also be employed (after the guide wire 530 isremoved) to deliver a controlled amount of medicament or other chemicalto that portion of the brain 10. Additionally, for these types of uses,an embodiment with an inflatable balloon (not pictured) to forcemedication diffusion in a particular direction in a vessel may beuseful. The balloon may occlude a vein while medication is delivereddistal to the balloon site, preventing blood flow from dispersing thetherapeutic agent away from the target region.

Referring to FIGS. 6A-E, a mapping-ablation device 600 may be adapted topenetrate a cerebral vein 20 so as to deliver electrodes 620 and 622through the wall of the cerebral vein 20 and into the brain tissue 30.In this embodiment, the device 500 includes two electrodes 620 and 622that are capable of detecting electrophysiological signals in a portionof a brain 10, capable of detecting impedance parameters in a portion ofthe brain 10, or both. The elongated body 610 may comprise a flexiblecatheter having an inner conduit through which one or more electricalwires or conductive lines (not shown in FIGS. 6A-E) may pass. Theelectrical wires may extend through the elongated body 610 so as toelectrically couple to the electrodes 620 and 622, and the electricalwires may extend out of a proximal end (not shown in FIGS. 6A-E) of theelongated body 610 so as to electrically couple with a control unit,such as an electrophysiological mapping control and display system or animplantable control unit.

As previously described, the guide wire 630 may comprise a flexible,biocompatible material having a distal end 632 (FIG. 6C) that issteerable or may be controllably bendable. As such, the guide wire 630may percutaneously enter the patient's jugular or femoral vein and thenmay be directed to a targeted portion of the brain through one or morecerebral veins 20. The elongated body 610 may include an inner conduitextending therethrough that is capable of sliding over the guide wire630. The user may then deliver the electrodes 620 and 622 to thetargeted portion by sliding the elongated body 610 over the guide wire630 toward the distal end 632 of the guide wire 630. In theseembodiments, the outer diameter of the elongated body 610 may be sizedto safely pass through the inside of various cerebral veins 20.

Referring to FIGS. 6B-E, the mapping ablation device 600 may include aneedle device 635 configured to slide over the guide wire 630 so as topuncture the wall of a cerebral vein 20. A user may direct the needledevice 635 to form an opening 25 in the vein 20 so that the guide wire630 may pass through the wall of the vein 20 into the brain tissue 30.In general, the needle device 635 may be wholly or partially withdrawnaway from opening 25 in the vein 20 before the guide wire 630 isdirected into the brain tissue 630 (refer to FIG. 6C). The distal end612 of the elongated body 610 may be directed over the guide wire 630through the opening 25 an into the brain tissue 30. In some embodiments,the electrodes 620 and 622 may be positioned to directly contact thebrain tissue 30. As previously described in other embodiments, the usermay be able to analyze an electrophysiological map of a patient's brain10 and, at the same time or within a short time period before or afterthe mapping process, may be able to apply ablation energy for treatmentof a nervous system disorder. In this embodiment, the electrodes 620 and622 may be in direct contact with the brain tissue 30 during the mappingprocess and during the ablation process. In such circumstances, thebrain tissue 30 that requires ablation treatment may be locally ablatedwith a reduced likelihood of unnecessarily ablating non-targeted tissue.As shown in FIG. 6E, the opening 25 formed in the cerebral vein 20 maywholly or partially sealed by delivering ablation energy to the opening25 after the electrodes 620 and 622 have been withdrawn from the braintissue 30 and into the vein 20. The ablation energy from the electrodes620 and 622 in the vein 20 may cause the opening 25 in the vein toeffectively seal, thereby preventing excessive blood flow from the vein20 into the brain tissue 30.

As previously described, the user may direct the electrodes 620 and 622to different portions of the brain 10 using the guide wire 630 (andusing the needle device 635 when there is a need to penetrate throughthe cerebral vein 20 into the brain tissue 30). In those different brainportions, the user may employ the electrodes 620 and 622 to detect theelectrophysiological signals to map at least a portion of the brain 10using, for example, an electrophysiological mapping and display system(e.g., a digital EEG display system or the like). If the mapping processdoes not reveal a portion of the brain 10 that is affected by a nervoussystem disorder or that otherwise requires treatment, the user maydirect the electrodes 620 and 622 to a different portion of the brain10.

If the mapping process reveals a portion of the brain 10 that isaffected by a nervous system disorder of otherwise requires treatment,the user may thereafter deliver ablation energy to the affected tissue(e.g., brain tissue 30) using the electrodes 620 and 622. Accordingly,in some embodiments, a user may view a high-resolution map of at least aportion of the patient's brain and may contemporaneously treat thatportion of the brain with ablation energy, all of which may beaccomplished without an invasive procedure that requires an opening tobe formed in the patient's cranium. As previously described, variousimaging modalities can be used to identify the location of electrodes620 and 622 relative to other electrodes and anatomic structures.

Also as previously described, the guide wire 630 may be removed from theinner conduit of the elongated body 610 after the electrodes 620 and 622are delivered to a targeted portion of the brain 10. Then, the innerconduit may be used to deliver a medicament delivery catheter (not shownin FIGS. 6A-E), such as a syringe catheter that is capable of dispensinga controlled amount of a medicament or other chemical.

Referring to FIG. 7A, a mapping-ablation device 700 may include aninflatable balloon structure 730 that permits the both internal andexternal cooling of the device 700. In this embodiment, the device 700includes two electrodes 720 and 722 that are capable of detectingelectrophysiological signals in a portion of a brain 10, capable ofdetecting impedance parameters in a portion of the brain 10, or both.The elongated body 710 may comprise a flexible catheter having a conduitthrough which one or more electrical wires or conductive lines (notshown in FIG. 7A) may pass. The electrical wires may extend through theelongated body 710 so as to electrically couple to the electrodes 720and 722, and the electrical wires may extend out of a proximal end (notshown in FIG. 7A) of the elongated body 710 so as to electrically couplewith a control unit, such as an electrophysiological mapping control anddisplay system or an implantable control unit. As previously described,the distal end 712 of the elongated body 710 may be steerable (e.g., viasteering wires or via a guide wire) so that the electrodes 720 and 722may be directed through one or more cerebral veins 20 to a targetportion of the brain. In some embodiments, the electrodes 720 and 722may be capable of delivering RF ablation energy. For example, electrodes720 and 722 may comprise opposite poles such that resistive heatingoccurs between the electrodes 720 and 722. In another example, theelectrodes 720 and 722 may interact with an opposite electrode poledisposed elsewhere so that resistive heating occurs between the salinesolution in the balloon structure 735 (charged by the electrodes 720 and722) and the opposite electrode pole (described in more detail below).

The balloon structure 730 may comprise a flexible material that can beinflated from a first, non-expanded state to a second, expanded state.When the balloon structure 730 is in the expanded state, the balloonstructure 730 may abut all or a portion of the vein wall 20. Theelongated body 710 may include an input conduit extending therethroughso that a liquid (e.g., a saline solution) flows toward the balloonstructure 730. The input conduit may terminate near the distal end 712of the elongated body 710 at one or more fluid input ports 735. Thefluid input ports direct the liquid (e.g., the saline solution) into theballoon structure 730 so as to expand the balloon. The liquid flowsthrough the balloon volume and into at least one fluid exit port 734.The fluid exit port 734 is in fluid communication with a drain conduitthat extends through the elongated body 710 so as to drain the liquidfrom the balloon. The flow of liquid through the balloon may becontrolled so as to maintain the balloon in the expanded state.

The liquid may be cooled to a temperature below the body temperature ofthe patient (e.g., may be cooled to room temperature) so that as thefluid flows internally through the elongated body 710, the elongatedbody may be substantially continuously cooled. In addition, because theliquid flows outside of the elongated body 710 (inside the volume of theballoon structure 730, at least a portion of the outer area of thedevice 700 may be cooled (e.g., the outer area of the distal end 712 maybe both internally and externally cooled). Because the device 700includes such internal-external cooling action, the device may becapable of delivering more localized ablation heat energy while reducingthe likelihood of unnecessarily ablating non-targeted tissue. Forexample, RF ablation energy may heat the surrounding tissue usingresistive heating (e.g., when the RF energy encounters the higherimpedance of human tissue, heat is produced). The internal-externalcooling of the device 700 provides the opportunity to delivering greatertotal energy to the targeted brain tissue without excessive heatingalong the outer surface of the electrodes 720 and 722. Such embodimentsmay increase the effectiveness of the ablation treatment and may reducethe likelihood of unnecessarily ablating healthy brain tissue.

Referring to FIGS. 7B-C, some embodiments of a mapping-ablation device750 may comprise a material that permits a limited amount of the liquid,such as the saline solution, to weep from the balloon structure 780. Inthis embodiment, the device 750 includes two electrodes 720 and 722 thatare capable of detecting electrophysiological signals in a portion of abrain 10, capable of detecting impedance parameters in a portion of thebrain 10, or both. The balloon structure 780 may comprise an flexiblematerial that can be inflated from a first, non-expanded state to asecond, expanded state. When the balloon structure 780 is in theexpanded state, the balloon structure 780 may abut all or a portion ofthe vein wall 20. The device 750 may include an internal cooling conduit754 (FIG. 7C) extending therethrough so that a liquid (e.g., a salinesolution) circulates through the elongated body to internally cool thedistal end 752. The internal cooling conduit 754 may loop near thedistal end 752 so as to return toward the proximal end (not shown) ofthe device 750. The device 750 may also include an inflation fluidconduit 755 (FIG. 7C) extending therethrough so that a liquid (e.g., asaline solution) is directed toward the balloon structure 780. Theinflation fluid conduit 755 may terminate at a port 785 near the distalend 752 so that fluid passing through the conduit 755 may inflate theballoon structure 780 and cause some portion of the fluid to weep fromthe balloon structure 780.

The electrodes 720 and 722 may act as a common pole that interacts withan opposite electrode pole disposed elsewhere (e.g., an electrode patchon the patient's scalp or an opposite electrode outside the balloonstructure 780. In these circumstances, the liquid in the balloonstructure 780 may comprise a saline solution (or other electricallyconductive material) so that the saline solution in electricalcommunication with the electrodes 720 and 722 serves as a “commonelectrode pole” that interacts with the opposite electrode pole disposedelsewhere. Because the balloon structure 780 may comprise a materialthat permits a limited amount of the liquid to weep, the liquid thatweeps from the balloon may further disperse the “common electrode pole”created when the saline solution is in electrical communication with theelectrodes 720 and 722. For example, RF ablation energy can be deliveredbetween the saline solution (both in the balloon 780 and weeping outsidethe balloon) and the opposite electrode pole disposed elsewhere so as toablate a localized, targeted tissue area.

Referring now to FIG. 8A, a mapping-ablation device 800 having a balloonstructure 830 may be directed to a target portion of the brain using aguide wire 840. In this embodiment, the device 800 includes twoelectrodes 820 and 822 that are capable of detectingelectrophysiological signals in a portion of a brain 10, capable ofdetecting impedance parameters in a portion of the brain 10, or both.The elongated body 810 may comprise a flexible catheter through whichone or more electrical wires or conductive lines (not shown in FIG. 8)may pass. The electrical wires may extend through the elongated body 810so as to electrically couple to the electrodes 820 and 822, and theelectrical wires may extend out of a proximal end (not shown in FIG. 8)of the elongated body 810 so as to electrically couple with a controlunit, such as an electrophysiological mapping control and display systemor an implantable control unit. The elongated body 810 may include anconduit 816 that is configured to slide over a guide wire 840. As such,the distal end 812 may by directed over the guide wire 840 so that theelectrodes 820 and 822 can be directed through one or more cerebralveins 20 to a target portion of the brain.

As previously described, the balloon structure 830 may comprise anflexible material that can be inflated from a first, non-expanded stateto a second, expanded state. When the balloon structure 830 is in theexpanded state, the balloon structure 830 may abut all or a portion ofthe vein wall 20. The elongated body 810 may include an input conduit815 extending therethrough so that a liquid (e.g., a saline solution)flows toward the balloon structure 830. The input conduit may terminatenear the distal end 812 of the elongated body 810 at one or more fluidinput ports 835. The fluid input ports direct the liquid (e.g., thesaline solution) into the balloon structure 830 so as to expand theballoon. The liquid flows through the balloon volume and into one ormore fluid exit ports 834. The fluid exit ports 834 are in fluidcommunication with a drain conduit 814 that extends through theelongated body 810 so as to drain the liquid from the balloon structure830. The flow of liquid through the balloon structure 830 may becontrolled so as to maintain the balloon structure 830 in the expandedstate. The liquid may be cooled to a temperature below the bodytemperature of the patient (e.g., may be cooled to room temperature) sothat the device 800 provides an internal-external cooling action, aspreviously described.

In some embodiments, the electrodes 820 and 822 may act as a common polethat interacts with an opposite electrode pole disposed elsewhere. Theopposite electrode pole may be part of an electrode patch 825 disposedon the patient's scalp. As such, the brain tissue between electrodes 820and 822 and the electrode patch 825 may be targeted for ablationtherapy. In these circumstances, the liquid in the balloon structure 830may comprise a saline solution (or other electrically conductivematerial) so that the saline solution in electrical communication withthe electrodes 820 and 822 serves as a “common electrode pole” thatinteracts with the opposite electrode pole of the electrode patch 825.The RF ablation energy can be delivered between the saline solution inthe balloon structure 830 and the electrode patch 825, therebydispersing the ablation energy in a localized, targeted tissue area 35.As previously described, RF ablation energy may heat the targeted tissueusing resistive heating (e.g., when the RF energy encounters the higherimpedance of human tissue, heat is produced). The internal-externalcooling of the device 800 provides the opportunity to delivering greatertotal energy to a localized area 35 of brain tissue without excessiveheating along the outer surface of the electrodes 820 and 822. Suchembodiments may increase the effectiveness of the ablation treatment andmay reduce the likelihood of unnecessarily ablating healthy braintissue.

It should be understood that the electrodes 820 and 822 or other portionof the mapping-ablation device 800 may be configured to deliver one moretypes of ablation energy, including RF energy, ultrasound energy, andmicrowave energy. In some embodiments, the mapping-ablation device 800may be configured to deliver various types of energy (e.g., RF energy,ultrasound energy, microwave energy, and the like) simultaneously orsequentially to targeted portions of the brain.

In some embodiments, the balloon structure 830 may comprise a materialthat permits a limited amount of the liquid, such as the salinesolution, to weep 837 from the balloon structure 830. In suchcircumstances, the liquid that weeps from the balloon may furtherdisperse the “common electrode pole” created when the saline solution isin electrical communication with the electrodes 820 and 822. In otherwords, the RF ablation energy can be delivered between the salinesolution (both in the balloon and weeping outside the balloon) and theelectrode patch 825 to ablate a localized, targeted tissue area 35. The“common electrode pole” may be effectively widened by the weeping 837saline solution so as to promptly distributed the ablation energy tocontrolled area 35 without having to reposition the balloon structure830 in the vein. Additionally, different liquids could be selected foruse depending on the clinical situation, differentially affecting thesize of the ablative lesion. Hypertonic solutions, for example, whichare excellent electrical conductors, could be employed when largerlesion size is desired.

It should be understood that, in other embodiments, the device may notemploy an opposite electrode pole (e.g., electrode patch 825) disposedoutside of the balloon structure 830. For example, the electrodes 822and 820 may be used to deliver RF ablation energy while the electrodesare in contact with the liquid in the balloon structure 830, therebycausing the liquid in the balloon structure 830 to serve as an ablationdelivery instrument In such circumstances, the heat generated fromresistance in the liquid may be delivered to the brain tissue 30 throughthe saline solution.

Referring now to FIG. 8B, the mapping-ablation device 800 may include anopposite pole electrode 852 that can be disposed in a position spacedapart from the electrodes 820 and 822. The opposite pole electrode 852may be capable of more accurately directing the ablation energy to alocalized area 35 of the brain tissue 30. In one exemplaryimplementation, the guide wire 840 (FIG. 8A) may be withdrawn from theconduit 816 so that an electrode delivery sheath 850 may be passedtherethrough. The electrode delivery sheath 850 may include a conduitthrough with the electrode rod 851 is passed. The opposite poleelectrode 852 may be disposed near a distal end of the rod 851 such thatthe position of the electrode 852 may be adjusted by shifting the rod851 within the delivery sheath 850.

The opposite pole electrode 852 may be adapted to pass through the wallof the cerebral vein 20 and into the brain tissue 30 to provide moreaccurate direction of the ablation energy to a localized area 35 of thebrain tissue 30. For example, the electrode 852 may include aneedle-like tip that permits the electrode 852 to puncture the veinwall. In another example, the delivery sheath 850 may include a needledevice (similar to needle device 635 of FIG. 6B) to puncture the veinwall. The electrode rod 851 may be steerable or may comprise ashape-memory member (to cause a bend when the rod 851 is outside thesheath 850) so that the opposite pole electrode 852 may be directed intothe brain tissue 30. The opposite pole electrode 852 may be electricallycoupled to a wire or a conductive line that extends through the rod 851to a proximal end (not shown in FIG. 8B) for connection to a controlunit.

In this embodiment, the mapping-ablation device 800 delivers ablationenergy to the localized area 35 of brain tissue between the electrodes820 and 822 and the opposite pole electrode 852. A user may shift theselected area to be ablated by shifting the position of the oppositepole electrode 852 relative to the distal end 812 (e.g., where theelectrodes 820 and 822 are disposed). In these circumstances, the liquidin the balloon structure 830 may comprise a saline solution (or otherelectrically conductive material) so that the saline solution inelectrical communication with the electrodes 820 and 822 serves as a“common electrode pole” that interacts with the opposite pole electrode852. The RF ablation energy can be delivered between the saline solutionin the balloon structure 830 and the opposite pole electrode 852,thereby dispersing the ablation energy in a localized, targeted tissuearea 35. As previously described, RF ablation energy may heat thetargeted tissue using resistive heating (e.g., when the RF energyencounters the higher impedance of human tissue, heat is produced). Theinternal-external cooling of the device 800 provides the opportunity todelivering greater total energy to a localized area 35 of brain tissuewithout excessive heating along the outer surface of the electrodes 820and 822. Such embodiments may increase the effectiveness of the ablationtreatment and may reduce the likelihood of unnecessarily ablatinghealthy brain tissue.

Referring to FIGS. 9A-B, a mapping-ablation device 900 may be coupled toan implantable control unit 930 configured to monitor theelectrophysiological signals and/or impedance parameters in the brain 10and configured to respond to those signals and/or parameters. In thisembodiment, the device 900 includes at least one elongated body 910having one or more electrodes 920 and 922 disposed near a distal end 912of the body 910. (It should be understood, that the device 900 mayinclude a plurality of elongated bodies similar to the embodimentdescribed in connection with FIG. 2.) The electrodes 920 and 922 may becapable of detecting electrophysiological signals in a portion of abrain 10, capable of detecting impedance parameters in a portion of thebrain 10, or both. The elongated body 910 may comprise a flexiblecatheter having a conduit through which one or more electrical wires orconductive lines (not shown in FIG. 9) may pass. The electrical wiresmay extend through the elongated body 910 so as to electrically coupleto the electrodes 920 and 922, and the electrical wires may extend outof a proximal end 913 of the elongated body 910 so as to electricallycouple with a control unit, such as the implantable control unit 930.The distal end 912 of the elongated body 910 may be steerable (e.g., viasteering wires or via a guide wire) so that the electrodes 920 and 922may be directed through one or more cerebral veins 20 to a targetportion of the brain, including portions in the frontal lobe, parietallobe, occipital lobe, temporal lobe, thalamus, hypothalamus, and thelike. For example, the distal end 912 of at least one elongated body 910may be delivered to a targeted portion of the temporal lobe where aseizure focus is known or predicted to exist in a patient's brain, andin such circumstances the mapping-ablation device 900 may be capable ofdetecting an treating the seizure-causing condition. In another example,the distal end 912 of the elongated body 910 may be delivered to thehypothalamus to ablate or stimulate neurons in the arcuate nucleus ofthe hypothalamus, which may be effective to treat obesity or otherconditions.

The implantable control unit 930 may be configured to be implantedproximal to the patient's clavicle (not shown) of another portion of thepatient's body. For example, the control unit 930 may include a mountingplate 932 that is configured to receive bone screws for mounting to theclavicle or to receive an engagement cable for wrapping around a portionof the clavicle. The control unit 930 may have an outer shape that isadapted to abut along a portion of the clavicle or along another portionof the patient's body. The control unit may be surgically implantedafter the electrodes 920 and 922 have been directed to a targetedportion of the brain using, for example, a percutaneous entry throughthe patient's jugular vein. After the electrodes 920 and 922 have beenproperly positioned in the patient's brain, the proximal end 913 of theelongated body 910 may be connected to the control unit 930 (eitherbefore or after the control unit is mounted to the clavicle or otherbody portion).

The control unit 930 may include a power source 934 that provideselectrical energy to the various components of the control unit 930. Insome circumstances, the power source 934 may also provide electricalenergy to the electrodes 920 and 922 for purposes of stimulating tissueor for purposes of ablating tissue. The power source 934 may comprise abattery device or the like. In some circumstances, the power source maybe periodically recharged using a wireless inductive coil.

In some embodiments, the control unit 930 may include a data port 936 toconnect with a cable or other jack so that data may be transferred to orfrom the control unit 930. In some embodiments, the control unit mayinclude software and filter settings that may be updated or otherwiseadjusted, depending on the patient's needs. In those circumstances, thedata port 936 may be used to communicate data to or the control unit930.

The control unit 930 may include a wireless transmitter 937, a wirelessreceiver 938, or both. The wireless transmitter 937 may be configured totransmit a signal when a predetermined parameter or set of parameters isdetected. For example, the electrodes 920 and 922 may detectelectrophysiological signals, impedance parameters, or both and suchdata may be received by the control unit 930. The control unit 930 mayinclude one or more controller circuits that use this data to predict animpending vascular event (e.g., a stroke), an electrical event (e.g., aseizure), or both, as described in more detail below. In responsethereto, the control unit 930 may employ the transmitter 937 to send asignal that can be used to alert the patient of the imminent event(e.g., a stroke or seizure), contact emergency care providers, or thelike. The wireless receiver 938 may be employed to receive updates ormodifications to the control units internal settings or software, toreceive a command sent from a communication device outside the patient'sbody (e.g., a command to stimulate the brain 10 using the electrodes 920and 922), or both.

Still referring to FIGS. 9A-B, the control unit 930 may also includecontroller circuit 939 configured to receive data signals from theelectrodes 920 and 922 and to initiate a response to those data signalsif predetermined parameters are met. In one non-limiting example, thecontroller circuit 939 may include at least one filter that electricallyfilter the data signals received from the electrodes 920 and 922 in thebrain 10 and that output. In some embodiments, the filter may be an openfilter having a high pass of 20 MHz and a low pass of 400 to 500 MHz. Inthis non-limiting example, the filter amplitude may be about 0.05 mvoltsto about 4 mvolts and the filter slew may be approximately 0.3 toapproximately 3 mvolts/msec. As previously described, the data port 936of the wireless receiver 938 may be used to update or adjust thesefilter settings depending on the particular portion of the brain that isbeing mapped. In some embodiments, the filter may be controlled by adynamic algorithm that will set the proper parameters based upon thelocation of the electrodes 920 and 922 in the brain 10.

The controller circuit 939 may comprise integrated circuits, softwarestored on computer memory, or other components that are programmed topredict an imminent vascular event (e.g., a stroke), electrical event(e.g., a seizure), or both based upon the data signals from theelectrodes 920 and 922 in the brain 10. In some instances, theelectrophysiological signals in the brain 10, the impedance parametersin the brain, or both may become measurably abnormal in the momentsbefore a vascular event (e.g., a stroke) or electrical event (e.g., aseizure). The controller circuit 939 or other portion of the controlunit 930 may process the incoming signals to monitor the brain activity.The controller circuit 939 may comprise a computer memory unit thatstored data indicating normal brain activity. The controller circuit 939may be configured to receive data signals from the electrodes 920 and922 and to compare the data signals with normal brain activity datastored by the control unit 930. If abnormal signals or parameters aredetected by the electrodes 920 and 922, the controller circuit 939 orother portion of the control unit 930 may respond. For example, a changein the threshold signal of 30 to 60% may indicate abnormal signals orparameters that triggers a response from the control unit 930.

The controller circuit 939 or other portion of the control unit 930 mayrespond to abnormal signals or parameters in a number of ways. Forexample, the control unit 930 may be configured to transmit a signalthat alerts the patient or a nearby receiver that an imminent vascularevent (e.g., a stroke) or electrical event (e.g., a seizure) may occur.Such an alert may prompt the patient or another person to contactemergency care providers for help. Types of alerts may include anaudible tone generated by the control unit 930 or an associated device,a small shock, or communication with a cell phone or other wirelesscommunication device. In another example, the control unit 930 may beconfigured to transmit a signal to an emergency care provider or to amonitoring station that indicates the patient's geographical location(e.g., the control unit 930 may be configured to transmit dataassociated with the patient's global positioning coordinates or otherGPS system). In a further example, the control unit 930 may respond toabnormal signals or parameters detected in the brain 10 by causing apacing stimulation signal to be delivered to the electrodes 920 and 922.The pacing stimulation signal may attempt to restore normal electricalactivity in the brain 10 by electrically stimulating at a predeterminedfrequency (e.g., at approximately 80% of the intrinsic frequency). Inanother example, the control unit 930 may be configured to apply adefibrillator shock or rapid pacing via the electrodes 920 and 922 inthe brain 10. This therapeutic electrical therapy may be configured toterminate seizure events. In yet another example, the device 900 mayinclude an inner conduit with a preset amount of medicament or otherchemical (e.g., a thrombolytic) so that the control unit 930 may beconfigured to release the medicament or other chemical (e.g., athrombolytic) to the portion of the brain near the electrodes 920 and922. The medicament or other chemical (e.g., a thrombolytic) may beeffective at treating the vascular event (e.g., a stroke) or electricalevent (e.g., a seizure) until the patient receive further medical care.

It should be understood that the control unit 930 may wirelesscommunicate with the electrodes 920 and 920 rather than using a wiredconnection via the elongated body 910. In such embodiments, the proximalend 513 of the elongated body 510 may be connected with the control unit930. Rather, a substantial portion of the elongated body 910 may beremoved from the patient's body while the electrodes 920 and 922 andother components remain in the brain 10. It should also be understoodthat in addition to monitoring electrical signals from within nervoustissue, the control unit may be used to detect embolic events. Forexample, the control unit may employ ultrasound interrogation ofvascular structures (e.g., carotid artery) adjacent to the veins (e.g.,jugular vein) in which the elongated body resides.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

1. An electrophysiological brain mapping device, comprising an elongatedbody having a distal end to pass through one or more cerebral veinsproximal to brain tissue, the elongated body defining a fluid inputconduit in fluid communication with a fluid input port near the distalend and defining a drain conduit in fluid communication with a drainport near the distal end; one or more electrodes to detectelectrophysiological signals in a portion of the brain and to deliverablation energy, the electrodes being disposed near the distal end ofthe elongated body; and a balloon structure disposed near the distal endso as to surround the fluid input port, the drain port, and theelectrodes, the balloon structure being adjustable from a non-expandedstate to an expanded state when a fluid flows from the input port and tothe drain port.
 2. The device of claim 1, wherein when the fluid flowsfrom the input port and to the drain port, the elongated body isinternally cooled by fluid flow through the fluid input conduit and isexternally cooled along the of the distal end surround by the balloon.3. The device of claim 1, wherein the electrodes deliver ablation energywhen the distal end is passed through the one or more cerebral veinsproximal to the brain tissue.
 4. The device of claim 3, wherein theelectrodes interact with an opposite pole electrode disposed outside thecerebral vein so as to ablate brain tissue between the electrodes andthe opposite pole electrode.
 5. The device of claim 4, wherein when theballoon structure is in an expanded state, the electrodes and the fluidin the balloon structure acts as a common pole electrode.
 6. The deviceof claim 1, wherein the balloon structure comprises a porous material sothat a limited amount of fluid weeps from the balloon structure when theballoon structure is in the expanded state.
 7. The device of claim 1,wherein the electrodes are electrically coupled to a control unit near aproximal end of the elongated body.
 8. The device of claim 7, whereinthe device is an electrophysiological mapping and display system havingone or more screens to display signals detected by the electrodes. 9.The device of claim 7, wherein the control unit is an implantablecontrol unit.
 10. The device of claim 9, wherein the implantable controlunit is configured to transmit a signal in response to abnormal brainactivity detected by the electrodes.
 11. An implantable control devicefor predicting an imminent event in a brain, comprising: a housingimplantable in a body of a patient; a controller circuit at leastpartially disposed in the housing, the controller circuit comprising atleast one filter to receive electrophysiological signals detected by oneor more electrodes disposed in a portion of a brain; and a wirelesstransmitter to transmit a signal to a device outside the body of thepatient in response to abnormal brain activity detected by theelectrodes, the wireless transmitter being electrically coupled to thecontroller circuit.
 12. The device of claim 11, further comprisingcomputer memory to store data signals indicating normal brain activity.13. The device of claim 12, wherein the controller circuit compares datafrom electrophysiological signals received by the filter from the one ormore electrodes disposed in the brain with the data signals indicatingnormal brain activity.
 14. The device of claim 11, wherein the wirelesstransmitter sends a signal indicative of an alert to the patient inresponse to abnormal brain activity detected by the electrodes.
 15. Thedevice of claim 11, wherein the wireless transmitter sends a signalindicative of a location of the patient in response to abnormal brainactivity detected by the electrodes.
 16. The device of claim 11, whereinthe controller circuit causes a stimulation pacing signal to bedelivered to the brain from the electrodes in response to abnormal brainactivity detected by the electrodes.
 17. The device of claim 11, whereinthe controller circuit causes a medicament to be delivered to the brainin response to abnormal brain activity detected by the electrodes.